Go to kohsamui from Bangkok's hua lamphong station down to Surat Thani , in southern Thailand. I love doing it this way as hua lamphong' s Art Deco train station is such a wonderful way to start off your vacation, with lots of little restaurants and snack bare and cool photo opportunities. Once in Surat Thani, take a boat to kohsamui . Express boats take about three you're and slower boats between five and six hours. You can also get a sleeper berth on the overnight train Bangkok to Surat thani, so you sleep most of the way anyway. Takes up to 16 hours by train plus 3-6 hours by boat. Prices run from 200 baht to around 800 ($5.50 to around $28) depending on what type of . Train you take